Back spacer for typewriters



Aug. 11, 1925. 1,549,082

0. A. HOKANSON BACK SPACER FOR TYPEIRII'BRS Filed July 17. 1920 2Sheets-Sheet 1 Aug'. 11, l 925.

1 v 08 O. A. HOKANSON J01 BACK SPACER FOR TYPEWRITERS Filed July17.;1920

Patented Aug. 11, 1925.

OTTO A. HOKANSON, OF WOODSTOCK,

ILLINOIS, Assrenon To WOODSTOCK 'rrrnwnrrnn COMPANY, OF WOODSTOCK,ILLINOIS, A. CORPORATION OF ILLINOIS.

BACK SPACER FOR- TYPEWRITERS.

Application filed. July 1'7,

1 0 all whom it may concern:

Be it known that I, O'r'ro A. HoKANsoN, a. citizen of the United States,residing at Woodstock, in the county of McHenry and State of Illinois,have invented certain new and useful Improvements in Back Spacers forTypewriters, of which the following is a specification.

This invention relates to that portion of typewriter mechanism by whichthe platen carriage may be fed in a reverse direction with a step bystep movement corresponding to the letter spacing on the typewrittensheet, and has for its object the provision of mechanism of thecharacter named which shall be of improved construction and operation.

The invention is exemplified in the combination and arrangement of partsshown in the accompanying drawings and described in the followingspecification, and it is more particularly pointed out in the appendedclaims.

In the drawings Fig. 1 is a fragmentary vertical sectional view of aportion of a typewriter having one embodiment of the present inventionapplied thereto;

Fig. 2 is a horizontal section substantially on line 22 of Fig. 1; and

Fig. 3 is a vertical section substantially on line 3-3 of Fig.2.

In the embodiment of the invention shown in the drawings, the numeral 10designates a base or main frame of a typewriter having a platen carriageframe 11 supported by arms 12 which are pivotally mounted at 13 on themain frame 10. The arms 12 are arranged to swing about their pivotalsupports 13 to move the platen carriage into operative position, asshown in Fig. 3, and also into a folded or inoperative position, inwhich the platen carriage is swung to the right on its pivotal supportsapproximately 180 degrees from the position shown in Fig. 3. The platencarriage frame 11 is provided with a platen carriage 14 arranged toslide along ways 15 on the carriage frame. The movement of the carriage14- is controlled by a rack 16 meshing with a pinion 17 which isconnected with an escapement wheel 18 journaled on the platen frame 11..Any usual and approved form of escapement 1920. Serial No. 396,887.

mechanism may be usedfor controlling the operation of the escapementwheel 18.

The main frame 10 of the typewriter is provided with a rear plate 19having laterally bent flanges 20 and 21 on which a bar 22 is mounted forlongitudinal sliding move. ment. A slot 23 is formed in one end of thebar 22 and a screw 24: passes through the slot into the flange 20 tohold the bar in place and to limit the longitudinal movement thereof. Asecond slot '25 isprovided in the opposite end of the bar and isarranged at an angle to the longitudinal axis of the bar, as shown inFig. 2. A screw 26 passes through the slot and is provided with anextension 27 to which is secured one end of a spring 28. The oppositeend of the spring 28 is attached to a lug 29 extending downwardly fromthe bar 22 so that the bar is normally drawn to the right, as viewed inFigs. 1 and 2. The end of the. bar 22 adjacent the slot 25 carries anupwardly projecting flange 30 having a dog 31 pivotally mounted at 32thereon.- A. spring 33 surrounds the pivot 32 and tends to rotate thedog 31 in a clockwise direction, as viewed inFig. 1. A stop 3Pis formedon the dog to strike the bar 22 and limitthe movement of the dog underthe influence. of the spring 33.

An arm 35 is out from the plate 19 of the typewriterframe and bentupwardly and rearwardly, as shown in Figs. 1 and 2, to form a stop forengaging a lug36 on the dog 31. The spring 28 jection 36 against thestop 35 so that the dog 31 is rotated against the tension of the spring33 into the position shown in Fig. 1. The dog 31 is provided with anacting face 37 positioned adjacent the escapement wheel 18 and when thebar 22 is shifted to the left against the tension of the spring 28 bymechanism to be described, the projection 36 will be released from thestop 35 and the spring 33 will swing the acting face 37 upwardly intothe plane of the escapement wheel 18 so that as the bar 22 continues tomove .to the left the face 37 of the dog 31 will engage one of the teethof the escapement wheel 18 and rotate the escapement wheel in a backwarddirection an amount corresponding to one of the spaces between theteethof the wheel. The escapement wheelwill, of course,

normally presses the probe retained in its new postion b the dogs bywhich it is controlled. The lange 30 is provided with an upwardlyextending tooth 3 arranged so that when the bar 22 1s moved to actuatethe dog 31 and rotate the escapement wheel, the tooth 30 will be movedinto a position in the rear of one of the teeth on the escapement wheelto prevent any danger of overthrow of the escapement wheel under theforce of the backspacing dog. Since the escapement wheel is connectedwith the pinion 1? which meshes withthe rack 16 the reverse movement ofthe escapement wheel will move the platen carriage backwardly an amountcorresponding to a letter space. By successively vibrating the bar 22the platen carriage may be fed backwardly by a step by step move mentany amount desired.

For moving the bar 22 the typewriter is provided with a back-spacing keylever 38 having an upwardly projecting arm 39. WVhen the platen carriageis in operating position the arm 39 engages a bell crank lever 40pivotally supported on a lug 41 extending downwardly from the lower faceof the platen carriage frame 11. A spring 42 is carried on the lug 41and normally holds the bell crank 40 in engagement with the arm39. Theupper end of the arm 39 isbeveled, as shown at 43, so that when theplaten carriage frame 11 moves downwardly into operating position thebell crank 40 will be guided by the beveled surface 43 into position infront of the arm 39. A link 44 is pivotally mounted at 45 on the bellcrank 40 and is provided with a slot 46 at its opposite end slidablysupported on a suspension pin 47 extending downwardly from the frame 11.The link 44 is provided with an opening 48 arranged to engage a spur 49bent upwardly from the bar 22. The opening 48 is of a greater width thanthe thickness of the spur 49 and the upper end of the spur is beveled toguide the spur into position in the opening 48 when the platen carriageframe moves into operating position. Operation of the back spacing keylever 38 will move the bell crank 40 and cause the link 44 to shift thebar 22 against the tension of the spring 38 which operation firstreleases the dog 31 until it swings into the plane of the escapementwheel 18. Further movement of the backspacing key lover will cause theend of the bar 22 to travel in the direction of the slot 25, thusbringing the operating face 37 of the dog 31 into contact with one ofthe teeth of'the escapement wheel 18 and rotate the escapement wheel toshift the platen carriage one space. hen the back spacing key isreleased the spring 42 will restore the link 44 to its originalposition, thus permitting the bar 22 and the dog 31 to return to theposition shown in Fig. 1.

The operation may, of course, be repeated as many times as desired. henthe backspacing mechanism is inactive the dog 31 is held in the positionshown in Fig. 1 by the stop 35 so that it does not interfere with therotation of the escapement wheel for controlling the forward movement ofthe platen carriage. Since the operating dog 31, together with itsactuating bar 22 are mounted on the stationary portion of the typewriterframe, the dog will always be in position to be brought into operativeengagement with the escapement wheel whenever the platen carriage frameis moved to its operating position. The movement of the platen carriageframe to operating position will also automatically establish connectionbetween the back-spacing key lever 39 and the actuating bar 22 throughthe medium of the bell crank 40 and link 44 mounted on the platencarriage frame. When the platen carriage frame is swung to its foldedposition the bell crank 40 and link 44 will be disconnected from theback-spacing key lever and the bar 22, respectively, thus disengagingthe backspacing key lever from the mechanism for engaging the escapementwheel. The operating connection is automatically restored upon return ofthe platen carriage frame to its operating position, as previous lyexplained. claim 1. In combination, a typewriter having a base frame anda platen carriage frame mounted thereon for movement into and out ofoperating position, an escapement wheel carried by said platen carriageframe and movable therewith, and backspacing mechanism comprising a partmounted on said base frame in position to engage said escape ment wheelwhensaid platen carriage frame is in its operating position.

2. In combination, a typewriter comprising a base frame, a platencarriage frame mounted on said base frame and movable into and out ofoperating position, a platen carriage movably mounted on said platencarriage frame, an escapement wheel on said platen carriage frame forcontrolling the movement of said carriage, and mechanism mounted on saidbase frame for engaging said esoapement wheel for imparting a backspacing movement to said platen carriage said escapement wheel beingmovable into and out of operative relation with said engaging mechanismwhen said platen carriage frame is moved into and out of operatingposition.

3. In combination, a typewriter comprising a main frame, a platencarriage frame having a platen carriage movably mounted thereon, meansfor supporting said platen carriage frame for movement into and out ofoperating position, escapement mechanism mounted on said platen carriageframe for controlling the movement of said platen carriage, and aback-spacing dog mounted on said main frame in position to cooperatewith said escapement mechanism, whensaiol platen carriage frame is inoperating position, to impart a back-spacing movement to said platencarriage.

4. In combination, a typewriter comprising a main frame, a platencarriage frame mounted on said main frame and movable into and out ofoperating position, a platen carriage movably mounted on said platencarriage frame, escapement mechanism mounted on said platen carriageframe for controlling the movement of said platen carriage, back-spacingmechanism comprising an oscillatory member mounted on said main frameand having a. dog pivotally mounted thereon in position to cooperatewith said escapement mechanism when said platen carriage frame is inoperating position, means for hOlCliIlg said dog out of the path ofmovement of said escapement mechanism when said oscillatory member is inone position, and resilient means for automatically moving said dog intoposition to engage said escapement mechanism when said oscillatorymember is actuated to perform a back-spacing operation.

5. A typewriter comprising a main frame, a platen carriage frame mountedon said main frame for movement into and out of operating position, aplaten carriage on said platen carriage frame, back-spacing mechanismcomprising a part mounted on said main frame and arranged to impart abackspacing movement to said platen carriage when said platen carriageframe is in operating position, a back spacer key mounted on said mainframe and means for automatically rendering said back-spacing mechanisminoperative when said platen carriage frame is moved out of operatingposition, said means comprising a connection for operatively connectingsaid key and'said beforementioned part when said platen carriage frameis in operative position.

6. A typewriter comprising a main frame, a platen carriage frame mountedon said main frame for movement into and out of operating position, aplaten carriage on said platen carriage frame, backspacing mechanismcomprising a part mounted on said main frame, a back-spacing key on saidmain frame, and means on said platen carriage frame for connecting saidback-spacing key with the said part of said back-spacing mechanism whensaid plat-en carriage frame is in operating position.

7. In a typewriter, a main frame, a platen carriage frame mountedthereon for move-- ment into and out of operating position, a platencarriage on said platen carriage frame, back-spacing mechanismcomprising a part mounted on said main frame and arranged to impart aback-spacing movement to said platen carriage when said platen carriageframe is in operating position, a backspacing key on said main frame,and means on said platen carriage frame for connecting said back-spacingkey with said part of said back-spacing mechanism, said means beingmovable with said platen carriage frame and arranged to automaticallyconnect said key and back-spacing mechanism part when said platencarriage frame is moved into operating position and to disconnect saidkey and back-spacing mechanism part when said platen carriage frame ismoved out of operating position.

8. A typewriter comprising a main frame and a platen carriage framemounted thereon for movement into and out of operating position,back-spacing mechanism comprising a part mounted on said main frame, aback-spacing key on said main frame, and connecting means for said keyand part, said connecting means being carried by said platen carriageframe and movable therewith to automatically disconnect said key andback-spacing part when said platen carriage frame is moved out ofoperating position. a

9. In a typewriter", a platen carriage, an escapement wheel forcontrolling said carriage, back-spacing mechanism for engaging saidescapement wheel to impart a backward movement to said carriage, saidmechanism comprising an oscillatory member 100 mounted for slidingmovement in a direction parallel to the plane of said wheel and having adog pivotally mounted thereon and movable about its pivot in a planetrans verse to the plane of movement of said es- 105 capement wheel,means for holding said dog out of operating position when saidoscillatory member is in one position, and resilient means for holdingsaid oscillatory member in said position.

10. A typewriter comprising a main frame, a platen carriage framemounted thereon for movement into and out of operating position, aplaten carriage movably mounted on said platen carriage frame, an 115escapement wheel for controlling the movement of said carriage on saidframe, backspacing mechanism comprising an oscillatory member mounted onsaid main frame,

a dog pivotally mounted on said oscillatory 120 member, resilient meansfor moving said oscillatory member in one direction, a stop for engagingsaid dog, when said oscillatory member is drawn by said resilient meansto the limit of its movement, to hold said dog 125 out of the plane ofsaid escapement wheel, a spring for automatically moving said' dog intoposit-ion to engage said escapement wheel when said oscillatory memberis moved in the opposite direction, a back-spac- Eng key lever mountedon said main frame, ated by said key lever when said platen car a bellcrank mounted on said platen carriage riage frame is in operatingposition.

frame and arranged to engage said key ievel' In testimony whereof I havesigned my 10 when said platen carriage frame is in opername to thisspecification on this 21st day ating positiom and means for connectingof J une, A. D. 1920.

said bell crank with said oscillatory member to permit said oscillatorymember to be oper- OTTO A. HOKANSON.

